Air circulating heater



NOV, Z3, 1937. C; R GRAHAM 2,()99,883

AIR C IRCULATING HEATER Filed IJune 2o, 193e s sheets-sheet 1 FICE-IE* A TTORNEY vNOV. 23, 1937. C, R GRAHAM Y 2,099,883

AIR CIRCULATING HEATER Filed June 20, 1936 3 Sheets-Sheet 2 il N!- 'I u @um INVENTOR. V/ence ra/ram BY @my A TTORNE Y Nov. 23, 1937.

Filed June 20, 1936 5 Sheets-Sheet 3 /0 Er 1E '7 F- 1 [E: E

INVENTOR. dare/76e ra/vam y YW l/ ATToRNEY Patented Nov. 23, 1937 UNITED STATES PATENT OFFICE AIR CIBCULATING HEATER Application June zo, 193s, serial No. 86,312

3 Claims.

This invention relates generally to circulating air heaters, such as are employed for heating dwellings or rooms. In one embodiment of the invention described herein, the heater is incorporated with a gas cooking range.

It is anv object of the `invention to provide a heater of the above character, characterized by a simple and eiilcient type of heating unit. This heating unit'is provided with iins or ribs for more effectively transferring heat to convexing currents of air, but the construction is such that these ns are integral with sheet metal walls, thus providing more eilective conduction of heat to the same, and eliminating welding operations.

Further objects of the invention will appear from the following description in which the preferred embodiments of the invention have been set forth in detail, in conjunction with the accompanying drawings.

Referring to the drawings:

Fig. 1 is a front elevational view of a gas range, incorporating an air circulating heater in ,accordance with the present invention.

Fig. 2 is an end view of the range illustrated in Fig. 1.

Fig. 3 is a cross-sectional detail taken along the line 3-3 of Fig. 2.

Fig. 4 is a side elevational view, of the heating unit incorporated in the air circulating heater provided in the -gas range of Figs. 1 to 3 inelusive.

Fig. 5 is a cross-sectional detail taken along the line 5-5 of Fig. 4.

Fig. 6 is a cross-sectional detail taken along the line 6-6 of Fig. 4.

Fig. '7 is a front elevational view, showing my air circulating heater incorporated in a range from which a trash burner box has been omitted.

Fig. 8 is a cross-sectional detail similar to Fig. 3.

Referring first to Figs. 1 to 3 inclusive, I have shown a range of the cabinet type, which in this instance is adapted to use natural or articial gas as a source of fuel. The closed top I of the cabinet II, forms the cooking surface. The cabinet can be provided with oven and broiler compartments, closed by the doors I2 and I3, utility drawers I l, and also in this instance a trash burner box I6. The trash burner box is disposed below one portion of the cooking surface I0, and adjacent the upright end wall I1.

Formed within the cabinet, and adjacent the outwardly bulged end wall Il, there is an air heating chamber I8. Chamber Il is formed in part by an upright wall portion I9, an inclined wall portion 20, and upright wall portion 2|, the last named wall being disposed between the trash burner box I6, and the upper part of the end wall4 I|. The front and rear sides of`chamber I8 are closed by suitable sheet metal walls, which may be the conventional Afront and rear walls of the cabinet. The end wall I`| is provided with upper and lower grill openings 23 and 24, to permit air from the room to flow into Y chamber I8, and then' out through the upper grill opening 23, after being heated. l

y The gas heating unit 25, disposed Within the compartment I8, can be best explained byreference to Figs. 4 to 6 inclusive. It consists of a pair of spaced upright side walls 26, joined together by the upper curved wall portion 21. Disposed upon the outer faces of the walls 26 are the heat transferring fins or ribs 28. All of the parts of the heating unit just described, are made from one single piece of sheet metal. Thus aA sheet of metal is iirst provided with parallel corrugations, to provide substantially U-shaped ns, as illustrated in Fig. 6. For a medial portion of this piece of sheet metal, which subsequently forms the wall portion 2l, the iins or corrugations are ilattened down upon the sheet of material, to form flattened folds, as indicated at 29. After this operation the sheet metal is bent over a suitable mandrel, to form the curved wall portion 21.

Ihe ends of the heating unit are closed by walls 3|, whereby the interior of the unit forms a space or path 32, for ilow of hot products of combustion. Near the upper part of the unit, one of the end walls 3| is provided with a vent opening 33, adapted to be connected to a flue. In order to provide a smoother and properly distributed ilow of products of combustion, a baille wall 3l can be provided, this wall having spaced openings 36 through which the products of combustion may ow. The lower edges of walls 26 can be reinforced by metal straps '31, and brackets 38 and 3S can be provided, for properly mounting the unit within the chamber IB.

Fig. 3 illustrates a gas burner II, dispose!!` at the lower end of the heating unit. Fig. 2 illustrates connection between the Avent opening '32, and a nue pipe I2.

'Ihe space within the cabinet occupied by the trash burner box I6, and also by the air circulating heater described above, can be segregated from the remainder of the cabinet by the partition wall 43. Thus a space 44 is provided between partition and the wall I9, for receiving the ash tray 45. Access to the front end of the heating unit can be accommodated by a door 41, on the front of the cabinet. Likewise another door 49 can be provided, to permit access to the grate bars of the trash burner box. The forward end wall of the heating unit can be provided with a ilame inspection window 5|, and alsogwlth an opening 52, for lighting a pilot burner.

Operation will be apparent from the above description. When the burner Il is in operation, heated air from the compartment Il circulates upwardly and iiows out through the grill openings 23, and cooler air is drawn intothey lower grill openings 2l. The heating unit e'ectively transfers heat to the convection currents of air, and no buckling or cracking noise will be experienced when the burner is starting in operation, or after the burner is extinguished, because ofthe rein- 1 forcing action of the corrugations 2B. Y Themodification shown in Figs. 7 and 8 differs from that described above, in that the' trash burnervbox has been omitted. 'I'l'lus in this case the compartment 53, in which the heating unit 25 is disposed, is in part disposed below the space 54K, occupied by the burners 56 of the range. 'I'he end wall 51 likewise has upper and lower grill openings 58 and 59, for circulation oi' air to be heated.

I claim:

l. In an air heater, a pair of spaced upright side walls, an upper wall serving to join the up- .per edges of the side walls, all of said walls being formed of one continuous piece of sheet metal, the space between said walls serving as a iiow path for -hot products of combustion, and

aseries of parallel corrugations formed in said walls, said corrugations forming spaced upright fins extending outwardly from the side walls and being flattened to form compact folds in said upper wall.

3. In an air heater, a pair of spaced` upright side walls, an upper wall servingtojoin the upper edges oi the side walls, all of lsaid Wallsvbeing formed of one continuous piece of sheet metal,

the space between said walls serving to form a flow path for hot products 'of combustion, and a series oi parallel `corrugations formed in said walls, said corrugations forming U-shaped iin sections extendingV outwardly from the side walls, and being flattened to form compact ,folds in vsaid upper wall. l

CLARENCE R. GRAHAM. 

